System and method for indicating return electrode contact

ABSTRACT

An electrosurgical system monitors and visually indicates a degree of contact between a return electrode and a patient&#39;s skin. The system includes an electrosurgical generator and a return pad. The return pad includes a return electrode, a lighting element, and a cable electrically and mechanically coupling the return electrode to the generator. The lighting element is configured to emit light based on the degree of contact between the return electrode and the patient.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/414,578, filed on May 16, 2019, now U.S. Pat. No. 11,185,362.

INTRODUCTION

The present disclosure relates generally to electrosurgical systems andmethods. More particularly, the present disclosure is directed toelectrosurgical systems and methods for return electrode monitoring,including monitoring the quality of contact between return electrodepads and the patient during electrosurgical procedures.

BACKGROUND

Energy-based tissue treatment is well-known in the art. Various types ofenergy (such as electrical, ultrasonic, microwave, cryogenic, heat,laser, and/or the like) are applied to tissue to achieve a desiredresult. Electrosurgery involves application of high radio frequencyelectrical current to a surgical site to cut, ablate, coagulate, seal orotherwise treat tissue. Energy-based surgical devices typically includean isolation boundary between the patient and the energy source.

In monopolar electrosurgery, the active electrode is typically part ofthe surgical instrument held by the surgeon and applied to the tissue tobe treated. One or more patient return electrodes are placed remotelyfrom the active electrode to carry the current back to the generator anddisperse current applied by the active electrode. The return electrodesusually have a large patient contact surface area to minimize heating atthat site. Heating is caused by high current densities which directlydepend on the surface area. A larger surface contact area results inlower localized heat intensity. Return electrodes are typically sizedbased on assumptions of the maximum current utilized during a particularsurgical procedure and the duty cycle (i.e., the percentage of time thegenerator is on).

Early types of return electrodes were formed as large metal platescovered with conductive jelly. Later, adhesive electrodes were developedwith a single metal foil covered with conductive jelly or conductiveadhesive. However, one challenge that arises from employing adhesiveelectrodes is that, if a portion of an adhesive electrode peels from thepatient, the contact area of the electrode with the patient decreases,thereby increasing the current density at the adhered portion and, inturn, decreasing the effectiveness of the treatment.

SUMMARY

In accordance with aspects of the disclosure, a patient return pad isprovided. The patient return pad includes a return electrode, a returnlead, a translucent sheathing, and a lighting element. The returnelectrode is configured to be coupled to a patient and to receiveelectrosurgical energy from an active electrode. The return lead has afirst end portion coupled to the return electrode and a second endportion configured to electrically couple the return electrode to anelectrosurgical energy source. The translucent sheathing is disposed onthe return lead. The lighting element is disposed at least partiallywithin the translucent sheathing and is configured to illuminate to emitlight through the translucent sheathing based on a measured impedance toindicate a degree of contact between the return electrode and apatient's tissue.

In an aspect of the present disclosure, the light emitted by thelighting element may be configured to be varied based on the measuredimpedance of the return electrode.

In another aspect of the present disclosure, the lighting element may bea plurality of lighting elements disposed along a length of the returnlead.

In an aspect of the present disclosure, the lighting element may bedisposed on the first end portion of the return lead adjacent the returnelectrode.

In yet another aspect of the present disclosure, the lighting elementmay be configured to emit a predetermined amount of light that isproportional to an amount of contact between the return electrode andthe patient's tissue.

In a further aspect of the present disclosure, the lighting element mayinclude at least one of an LED or a lighting fiber.

In an aspect of the present disclosure, the translucent sheathing maydefine a longitudinally-extending pathway.

In a further aspect of the present disclosure, the return electrode maybe a split foil electrode.

In accordance with aspects of the disclosure, an electrosurgical systemis presented. The electrosurgical system includes an electrosurgicalenergy source and a patient return pad. The electrosurgical energysource is configured to generate electrosurgical energy and includes amonitoring circuit. The patient return pad includes a return electrode,a return lead, a translucent sheathing, and a lighting element. Thereturn electrode is configured to be coupled to a patient and to receivethe electrosurgical energy from an active electrode. The monitoringcircuit is configured to be electrically coupled to the return electrodefor determining an impedance thereof. The return lead has a first endportion coupled to the return electrode and a second end portionconfigured to be electrically and mechanically coupled to theelectrosurgical energy source. The translucent sheathing disposed overthe return lead. The lighting source is disposed at least partiallywithin the translucent sheathing and is configured to illuminate to emitlight through the translucent sheathing based on the determinedimpedance. The electrosurgical energy source is configured to vary acharacteristic of the light emitted through the translucent sheathingbased on the determined impedance of the return electrode.

In yet another aspect of the present disclosure, the electrosurgicalenergy source may be configured to vary the characteristic of the lightemitted through the translucent sheathing in response to a change in thedetermined impedance.

In a further aspect of the present disclosure, the system may furtherinclude a monopolar electrosurgical instrument configured for electricalconnection to the electrosurgical energy source and for delivering theelectrosurgical energy.

In yet a further aspect of the present disclosure, the electrosurgicalenergy source may include an indicator light configured to turn on oroff based on the determined impedance.

In yet another aspect of the present disclosure, the translucentsheathing may include fiber optics for passing the light from theindicator light to an end portion of the translucent sheathing.

In a further aspect of the present disclosure, the monitoring circuitmay be configured to turn the indicator light on or off based on thedetermined impedance.

In yet a further aspect of the present disclosure, the characteristic ofthe light is at least one of brightness, intensity, or illuminance.

In yet another aspect of the present disclosure, the lighting elementmay include a plurality of lighting elements disposed along a length ofthe return lead.

In a further aspect of the present disclosure, the lighting element maybe disposed on the first end portion of the return lead adjacent thereturn electrode.

In an aspect of the present disclosure, the lighting element may beconfigured to emit a predetermined amount of light that is proportionalto an amount of contact between the return electrode and the patient'stissue.

In another aspect of the present disclosure, the lighting element mayinclude at least one of an LED or a lighting fiber.

In a further aspect of the present disclosure, a method for lighting areturn electrode is presented. The method includes generating, by anelectrosurgical energy source, electrosurgical energy, delivering theelectrosurgical energy to tissue from a monopolar electrosurgicalinstrument that is coupled to the electrosurgical energy source via acable, and emitting light through a translucent sheathing of the cable,and varying a characteristic of the light emitted through thetranslucent sheathing based on the determined impedance of the returnelectrode.

Further details and aspects of exemplary embodiments of the disclosureare described in more detail below with reference to the appendedfigures. Any of the above aspects and embodiments of the disclosure maybe combined without departing from the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will become more apparent in light of the following detaileddescription when taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic illustration of a system for indicating returnelectrode contact with a patient according to the present disclosure;

FIG. 2 is a block diagram of a generator of the system of FIG. 1;

FIG. 3 is a transverse cross sectional view of a cable of the system ofFIG. 1 illustrating a return lead and a translucent sheathing disposedthereabout;

FIG. 4 is a longitudinal cross sectional view of the cable of FIG. 3;

FIG. 5 is a schematic illustration of another embodiment of a system forindicating return electrode contact with a patient according to thepresent disclosure;

FIG. 6 is a transverse cross sectional view of a cable of the system ofFIG. 5; and

FIG. 7 is a longitudinal cross sectional view of the cable of FIG. 5.

DETAILED DESCRIPTION

Particular embodiments of the present disclosure are describedhereinbelow with reference to the accompanying drawings. In thefollowing description, well-known functions or constructions are notdescribed in detail to avoid obscuring the present disclosure inunnecessary detail.

A system and method for return electrode monitoring are provided. Thesystem includes a split foil electrode configured to be coupled to apatient for measuring electrical signals, a monitoring circuit of anelectrosurgical energy source electrically coupled to the split foilelectrode, and a cable electrically and mechanically coupling theelectrode to the electrosurgical energy source. The monitoring circuitis configured to measure an impedance of the split foil electrode. Thecable has a translucent sheathing and a lighting element disposed atleast partially within the translucent sheathing. The lighting elementis configured to illuminate based on the measured impedance to indicateto a clinician a degree of adherence of the return electrode to apatient's tissue.

FIG. 1 illustrates an electrosurgical system 100 including anelectrosurgical energy source, such as, for example, an electrosurgicalgenerator 160, an electrosurgical instrument 102 coupled to thegenerator 160, and a patient return pad 104 coupled to the generator 160via a return cable 110. The electrosurgical instrument 102 has one ormore active electrodes (not explicitly shown) for treating tissue of apatient P. The instrument 102 may be a monopolar instrument includingone or more active electrodes (such as, for example, an electrosurgicalcutting probe, ablation electrode(s), and/or the like). ElectrosurgicalRF energy is supplied to the instrument 102 by the generator 160 via anactive electrosurgical cable 106, which is connected to an active outputterminal, allowing the instrument 102 to coagulate, ablate and/orotherwise treat tissue.

Although the generator 160 is described herein as delivering RF energy,this is by example only and should not be construed as limiting. Thegenerator 160 in various embodiments may additionally or alternativelydeliver any suitable type of energy, such as ultrasonic energy,microwave energy, energy of other portions on the electromagneticspectrum, and/or the like. The energy is returned to the generator 160through the patient return pad 104, as will be described. The generator160 includes input controls (for example, buttons, activators, switches,touch screen, etc.) for controlling the generator 160. In addition, thegenerator 160 may include one or more display screens for providing theuser with variety of output information (for example, intensitysettings, treatment complete indicators, etc.). The controls allow theuser to adjust power of the RF energy, waveform, and other parameters toachieve the desired waveform suitable for a particular task (forexample, coagulating, cauterizing, intensity setting, etc.). Theinstrument 102 may also include a plurality of input controls that maybe redundant with certain input controls of the generator 160. Placingthe input controls at the instrument 102 allows for easier and fastermodification of RF energy parameters during the surgical procedurewithout requiring interaction with the generator 160.

Referring now to FIG. 2, there is shown a block diagram of exemplarycomponents of the electrosurgical generator 160 in accordance withaspects of the disclosure. In the illustrated embodiment, the generator160 includes a controller 161, a power supply 164, a radio-frequency(RF) energy output stage 162, a monitoring circuit 166, and one or moreplugs 169 that accommodate various types of electrosurgical instruments.The generator 160 can include a user interface (not shown), whichpermits a user to select various parameters for the generator 160, suchas mode of operation and power setting. In various embodiments, thepower setting can be specified by a user to be between zero and a powerlimit, such as, for example, five watts, thirty watts, seventy watts, orninety-five watts.

The electrosurgical generator 160 may be any suitable type of generatorand may include a plurality of connectors to accommodate various typesof electrosurgical instruments (e.g., monopolar, bipolar, and/or thelike). The electrosurgical generator 160 may also be configured tooperate in a variety of modes, such as ablation, cutting, coagulation,cutting/coagulation blend, sealing, or any combination thereof. Theelectrosurgical generator 160 may include a switching mechanism (e.g.,relays) to switch the supply of RF energy among the one or more plugs169 to which various electrosurgical instruments may be connected. Forexample, when an electrosurgical instrument, e.g., instrument 102, isconnected to the electrosurgical generator 160, the switching mechanismswitches the supply of RF energy to the plug 169 to which instrument 102is connected. In embodiments, the electrosurgical generator 160 may beconfigured to provide RF energy to a plurality of instrumentssimultaneously.

The monitoring circuit 166 of the generator may include a plurality ofsensors, e.g., an RF current sensor, an RF voltage sensor, and/or thelike. Various components of the generator 160, e.g., the RF output stage162 and the RF current and voltage sensors 166A, 166B of the monitoringcircuit 166, may be disposed on a printed circuit board (PCB). The RFcurrent sensor 166A of the monitoring circuit 166 may be coupled to theactive electrode and provides measurements of the RF current supplied bythe RF output stage 162. In embodiments, the RF current sensor 166A ofthe monitoring circuit 166 may be coupled to the return electrode. TheRF voltage sensor 166B of the monitoring circuit 166 is coupled to theactive terminal and a return terminal and provides measurements of theRF voltage supplied by the RF output stage 162. In embodiments, the RFcurrent and voltage sensors 166A, 166B of the monitoring circuit 166 maybe coupled to the active and return cables 106, 110 (FIG. 1), whichinterconnect the active and return terminals to the RF output stage 162,respectively.

The RF current and voltage sensors 166A, 166B of the monitoring circuit166 sense and provide the sensed RF voltage and current signals,respectively, to the controller 161 of the generator 160, which then mayadjust output of the power supply and/or the RF output stage 162 inresponse to the sensed RF voltage and current signals. The sensedvoltage and current from the monitoring circuit 166 are fed to ananalog-to-digital converter (ADC) 168 of the generator 160. The ADC 168samples the sensed voltage and current to obtain digital samples of thevoltage and current of the RF output stage 162. The digital samples areprocessed by the controller 161 and used to generate a control signal tocontrol the DC/AC inverter of the RF output stage 162 and thepreamplifier. The ADC 168 communicates the digital samples to thecontroller 161 for further processing. Examples of the processinginclude deriving the impedance of a return electrode 108 (FIG. 1) fromthe sensed voltage and current.

The monitoring circuit 166 may include a hand switch closure detectionsensor (not explicitly shown) configured to detect closure of a handswitch of the surgical instrument 102, a return electrode monitoringsensor (not explicitly shown) configured to detect an impedanceassociated with the return electrode 108 (e.g., for embodiments wherethe surgical instrument 102 is a monopolar electrosurgical instrument),a temperature sensor (not explicitly shown), a mechanical force sensor(not explicitly shown), and/or any other suitable type of sensor.

The generator 160 may include a light source 170 (FIG. 1) configured toindicate the detected impedance associated with the return electrode 108(e.g., a neutral electrode indication light emitted from theelectrosurgical generator 160). In various embodiments, the light source170 may include, but is not limited to an LED, an incandescent bulb, ora XENON source. The light source 170 may be powered by the power supply164 or an external battery.

With reference to FIGS. 1, 3, and 4, the patient return pad 104 of theelectrosurgical system 100 generally includes a return electrode 108 anda return cable 110. The return electrode 108 is configured to bepositioned in contact with the patient P and return the electrosurgicalenergy to the generator 160 by way of the return cable 110. Theelectrosurgical system 100 may include a plurality of return electrodes108 that are arranged to minimize the chances of tissue damage bymaximizing the overall contact area with the patient P.

FIGS. 3 and 4 are cross sections of the return cable 110 of the patientreturn pad 104. The return cable 110 is configured for illuminationbased on the impedance determined by the monitoring circuit 166 of thegenerator 160. The return cable 110 has a first end portion 110 acoupled to the return electrode 108 and a second end portion 110 bconfigured to be detachably coupled to an electrosurgical energy source,such as the generator 160 (FIG. 2).

The return cable 110 includes a return conductor 112 (e.g., a returnlead), an insulator 114 disposed about the return conductor 112, alighting fiber 116 disposed about the insulator 114, and a translucentconductor sheathing 118 disposed about the lighting fiber 116. Thereturn conductor 112 is coupled to the RF output stage 162 (FIG. 2) ofthe generator 160 and to the monitoring circuit 166 for return electrodemonitoring. The return conductor 112 is configured to electricallycouple the return electrode 108 to the generator 160. The returnconductor 112 may be any suitable conductive material for an electrodelead (e.g., copper). The conductor 112 has a first end portion 112 acoupled to the return electrode 108 and a second end portion 112 bconfigured to be detachably coupled to an electrosurgical energy source,such as the generator 160 (FIG. 2).

The insulator 114 of the return cable 110 may be any suitable insulatingmaterial (e.g., silicone, PVC, TFE, Alcryn, Cellular Polyethylene,Ethylene Propylenediene Monomer Rubber, etc.). The lighting fiber 116extends from the generator 160 to the return electrode 108 and isdisposed within the translucent conductor sheathing 118. The lightingfiber 116 is configured to facilitate the passage of light therealong.In embodiments, instead of a lighting fiber 116, the return cable 110may define a longitudinally-extending lumen between the insulator 114and the translucent conductor sheathing 118 for guiding light from thelight source 170 of the generator 160 (FIG. 2) to the second end portion110 b of the return cable 110. The first end portion 110 a of the returncable 110 may be coupled to a location of the generator 160 adjacent thelight source 170, such that light emitted from the light source 170 mayenter the return cable 110 via the first end portion 110 a thereof.

Light is transmitted from the light source 170, through the lightingfiber 116, and emitted out the translucent conductor sheathing 118. Themonitoring circuit 166 may control the light source 170 of the generator160 to illuminate based on the impedance of the return electrode 108detected by the monitoring circuit 166. Characteristics of the lightemitted by the light source 170, such as brightness, intensity,illuminance, etc., may be predetermined and/or varied in proportion tothe impedance and/or conductivity of the return electrode 108 (e.g.,light brightness increases as impedance of the return electrodeincreases to provide a conspicuous indication of poor contact betweenthe return electrode 108 and the patient P). In embodiments, only thesecond end portion 110 b of the return cable 110 may have thetranslucent conductor sheathing 118, whereas the remaining portion ofthe return cable 110 has an opaque sheathing. As such, when the lightsource 170 is activated, the light travels through the opaque sheathingto the second end portion 110 b of the return cable 110, whereupon thelight transmits out of the distal second end portion 110 b of the returncable 110.

During an electrosurgical procedure, the return electrode 108 (FIG. 1)of the return pad 104 is placed on tissue of a patient P (e.g., skin)and the monopolar electrode of the surgical instrument 102 is activatedto treat tissue. During treatment, the electrosurgical energy passesfrom the generator 160, through the electrosurgical instrument 102 andinto a patient P to treat the tissue. The electrosurgical energy thentravels from the tissue back to the electrosurgical generator 160 viathe return pad 104. Prior to and/or during the procedure, the monitoringcircuit 166 of the generator 160 determines impedance of the returnelectrode 108. In particular, the monitoring circuit 166 senses andprovides the sensed RF voltage and current signals of theelectrosurgical energy passing through the return electrode to thecontroller 161 of generator 160, which may adjust output of the powersupply and/or the RF output stage 162 in response to the sensed RFvoltage and current signals. The sensed voltage and current signals areprocessed by the controller 161 and an impedance value of the returnelectrode 108 is determined. Light is transmitted from the light source170, through the lighting fiber 116, and emitted out the translucentconductor sheathing 118 so that a surgeon is able to see the illuminatedreturn cable 110 in their peripheral vision without having to move theirhead to see the indicator light, e.g. light source 170, on the generator160. In this way, the illuminated return cable 110 provides the surgeonwith a conspicuous visual indication of contact quality between thereturn electrode 108 and the patient based on the determined impedanceof the return electrode 108.

In various embodiments, the impedance may be determined based on thesensed RF voltage and sensed RF current measurements. In embodiments,the impedance may be determined by conducting a sense pulse from theelectrosurgical instrument through the tissue and measuring the changein the pulse shape across the load, e.g. the tissue.

In one non-limiting example, the electrosurgical system 100 may detect aconductivity of the return electrode 108 as an impedance of about 100ohms and may have a predetermined luminance of about 1200 lumens. Inanother non-limiting example, the electrosurgical system 100 may detecta conductivity of the return electrode 108 as an impedance of about 1000ohms and may have a predetermined luminance of about 10 lumens.

FIG. 5 is a schematic illustration of an electrosurgical system 200according to another embodiment of the present disclosure. Theelectrosurgical system 200 is similar to the system 100 and will only bedescribed in the detail necessary to elucidate differences between thetwo.

The system 200 includes a patient return pad 204 including a returnelectrode 208 and a return cable 210 coupling the return electrode 208to an electrosurgical energy source, such as, for example, the generator160. The patient return pad 204 differs from the patient return pad 104of FIGS. 1-4 by having a lighting element 220 disposed within the returncable 210. Characteristics of the light emitted from lighting element220, such as brightness, intensity, illuminance, etc., may bepredetermined and/or varied by the controller 161 in proportion to theimpedance and/or conductivity of the return electrode 208. The lightingelement 220 may be powered by the generator 160 or an external powersource (e.g., a battery). The generator 160 may include a control unit172 operatively coupled to the lighting element 220. The control unit172 is configured to control the brightness of the lighting element 220to provide a visual indication of the impedance of the return electrode208.

FIGS. 6 and 7 are cross sections of the return cable 210. The cable 210is configured for illumination based on the detected impedance of thereturn electrode 208. The cable 210 has a first end portion 210 aconfigured to be electrically and mechanically coupled to the generator160, and a second end portion 210 b having the return electrode 208coupled thereto. The cable 210 includes a return conductor 212, aninsulator 214, a lighting fiber 216, a translucent conductor sheathing218, and the lighting element 220. The return conductor 212 isconfigured to electrically couple the return electrode 208 to thegenerator 160. The return conductor 212 may be any suitable conductivematerial for an electrode lead (e.g., copper). The conductor 212 has afirst end portion coupled to the return electrode 208 and a second endportion configured to be detachably coupled to an electrosurgical energysource, such as the generator 160 (FIG. 2).

The translucent conductor sheathing 218 defines alongitudinally-extending passageway 222 through which the lighting fiber216 extends. The lighting element 220 (e.g., one or more LEDs, bulbs,etc.) may be disposed within the lighting fiber 216. In variousembodiments, translucent or transparent materials other than lightingfiber 216 may be used. In embodiments, the LEDs may be in a series orparallel configuration. In other aspects, the lighting element 220 maybe disposed in air or a vacuum.

The lighting element 220 may include multicolor LEDs configured to lightpredetermined colors based on the detected impedance of the returnelectrode 208. For example, the LEDs may illuminate green at lowerimpedance values, denoting good contact between the patient P and thereturn electrode 208, yellow at a middle impedance value, and red atvery high impedance values, denoting poor contact between the patient Pand the return electrode 208.

The embodiments disclosed herein are examples of the disclosure and maybe embodied in various forms. For instance, although certain embodimentsherein are described as separate embodiments, each of the embodimentsherein may be combined with one or more of the other embodiments herein.Specific structural and functional details disclosed herein are not tobe interpreted as limiting, but as a basis for the claims and as arepresentative basis for teaching one skilled in the art to variouslyemploy the present disclosure in virtually any appropriately detailedstructure. Like reference numerals may refer to similar or identicalelements throughout the description of the figures.

The phrases “in an embodiment,” “in embodiments,” “in some embodiments,”or “in other embodiments” may each refer to one or more of the same ordifferent embodiments in accordance with the present disclosure. Aphrase in the form “A or B” means “(A), (B), or (A and B).” A phrase inthe form “at least one of A, B, or C” means “(A); (B); (C); (A and B);(A and C); (B and C); or (A, B, and C).” The term “clinician” may referto a clinician or any medical professional, such as a doctor, nurse,technician, medical assistant, or the like, performing a medicalprocedure.

The systems described herein may also utilize one or more controllers toreceive various information and transform the received information togenerate an output. The controller may include any type of computingdevice, computational circuit, or any type of processor or processingcircuit capable of executing a series of instructions that are stored ina memory. The controller may include multiple processors and/ormulticore central processing units (CPUs) and may include any type ofprocessor, such as a microprocessor, digital signal processor,microcontroller, programmable logic device (PLD), field programmablegate array (FPGA), or the like. The controller may also include a memoryto store data and/or instructions that, when executed by the one or moreprocessors, causes the one or more processors to perform one or moremethods and/or algorithms.

Any of the herein described methods, programs, algorithms or codes maybe converted to, or expressed in, a programming language or computerprogram. The terms “programming language” and “computer program,” asused herein, each include any language used to specify instructions to acomputer, and include (but is not limited to) the following languagesand their derivatives: Assembler, Basic, Batch files, BCPL, C, C+, C++,Delphi, Fortran, Java, JavaScript, machine code, operating systemcommand languages, Pascal, Perl, PL1, scripting languages, Visual Basic,metalanguages which themselves specify programs, and all first, second,third, fourth, fifth, or further generation computer languages. Alsoincluded are database and other data schemas, and any othermeta-languages. No distinction is made between languages which areinterpreted, compiled, or use both compiled and interpreted approaches.No distinction is made between compiled and source versions of aprogram. Thus, reference to a program, where the programming languagecould exist in more than one state (such as source, compiled, object, orlinked) is a reference to any and all such states. Reference to aprogram may encompass the actual instructions and/or the intent of thoseinstructions.

Any of the herein described methods, programs, algorithms or codes maybe contained on one or more machine-readable media or memory. The term“memory” may include a mechanism that provides (for example, storesand/or transmits) information in a form readable by a machine such aprocessor, computer, or a digital processing device. For example, amemory may include a read only memory (ROM), random access memory (RAM),magnetic disk storage media, optical storage media, flash memorydevices, or any other volatile or non-volatile memory storage device.Code or instructions contained thereon can be represented by carrierwave signals, infrared signals, digital signals, and by other likesignals.

It should be understood that the foregoing description is onlyillustrative of the present disclosure. Various alternatives andmodifications can be devised by those skilled in the art withoutdeparting from the disclosure. Accordingly, the present disclosure isintended to embrace all such alternatives, modifications and variances.The embodiments described with reference to the attached drawing figuresare presented only to demonstrate certain examples of the disclosure.Other elements, steps, methods, and techniques that are insubstantiallydifferent from those described above and/or in the appended claims arealso intended to be within the scope of the disclosure.

1-20. (canceled)
 21. A patient return pad, comprising: a returnelectrode configured to be coupled to a patient and to receiveelectrosurgical energy from an active electrode; a return lead having afirst end portion coupled to the return electrode and a second endportion configured to electrically couple the return electrode to anelectrosurgical energy source; and a translucent sheathing disposed overat least a portion of the return lead.
 22. The patient return padaccording to claim 21, further comprising a lighting element disposed atleast partially within the translucent sheathing.
 23. The patient returnpad according to claim 22, wherein the lighting element is configured toilluminate and emit light through the translucent sheathing based on ameasured impedance.
 24. The patient return pad according to claim 23,wherein illumination of the lighting element is configured to indicate adegree of contact between the return electrode and the patient.
 25. Thepatient return pad according to claim 23, wherein light emitted by thelighting element is configured to be varied based on the measuredimpedance of the return electrode.
 26. The patient return pad accordingto claim 22, wherein the lighting element includes a plurality oflighting elements disposed along a length of the return lead.
 27. Thepatient return pad according to claim 22, wherein the lighting elementis located at the first end portion of the return lead adjacent thereturn electrode.
 28. The patient return pad according to claim 22,wherein the lighting element is configured to emit a predeterminedamount of light that is proportional to an amount of contact between thereturn electrode and the patient.
 29. The patient return pad accordingto claim 22, wherein the lighting element includes at least one of anLED or a lighting fiber.
 30. The patient return pad according to claim21, wherein the translucent sheathing defines a longitudinally-extendingpathway.
 31. The patient return pad according to claim 21, wherein thereturn electrode is a split foil electrode.
 32. An electrosurgicalsystem, comprising: an electrosurgical energy source configured togenerate electrosurgical energy, the electrosurgical energy sourceincluding a monitoring circuit; and a patient return pad including: areturn electrode configured to be coupled to a patient and to amonitoring circuit associated with the electrosurgical energy source fordetermining an impedance of the return electrode; a return lead having afirst end portion coupled to the return electrode and a second endportion configured to be coupled to the electrosurgical energy source;and a translucent sheathing disposed about the return lead.
 33. Theelectrosurgical system according to claim 32, wherein the return padfurther includes a lighting element disposed at least partially withinthe translucent sheathing.
 34. The electrosurgical system according toclaim 33, wherein the lighting element is configured to illuminate andemit light through the translucent sheathing based on the determinedimpedance.
 35. The electrosurgical system according to claim 34, whereinthe electrosurgical energy source is configured to vary a characteristicof the light emitted through the translucent sheathing based on thedetermined impedance of the return electrode.
 36. The electrosurgicalsystem according to claim 33, wherein the electrosurgical energy sourceis configured to vary the characteristic of the light emitted throughthe translucent sheathing in response to a change in the determinedimpedance.
 37. The electrosurgical system according to claim 32, furthercomprising a monopolar electrosurgical instrument configured forelectrical connection to the electrosurgical energy source and fordelivering the electrosurgical energy.
 38. The electrosurgical systemaccording to claim 34, wherein the electrosurgical energy source has anindicator light configured to turn on or off based on the determinedimpedance.
 39. The electrosurgical system according to claim 38, whereinthe patient return pad includes fiber optics for passing the light fromthe indicator light to an end portion of the translucent sheathing. 40.The electrosurgical system according to claim 38, wherein the monitoringcircuit is configured to turn the indicator light on or off based on thedetermined impedance.